The State of Health of the Mount Lofty Ranges Catchments from a water quality perspective Government of South Australia The State of Health of the Mount Lofty Ranges Catchments from a water quality perspective Environment Protection Agency Department for Environment and Heritage GPO Box 2607, Adelaide SA 5001 Telephone 08 8204 2000 www.epa.sa.gov.au Mount Lofty Ranges Watershed Protection Office 85 Mt Barker Road, Stirling SA 5152 Telephone 1300 134 810 Facsimile 08 8139 9901 OCTOBER 2000 ISBN 1 876562 07 2 Front cover: First Creek at Waterfall Gully. The Environment Protection Agency's ambient water quality monitoring programme identified its waters as being one of the healthiest in South Australia. Its catchment is almost entirely native vegetation. Foreword The water resources and catchments The government is therefore of the Mount Lofty Ranges are critical committed to protecting and improving to the well-being of the people of water quality in the Mount Lofty Ranges Adelaide and the future development watershed. Programmes in excess of of South Australia. $28 million are already under way and The catchments of the Mount Lofty additional funds, amounting to a total Ranges are used for different purposes funding package of $40 million, will be including harvesting of drinking water, spent over the next five years on a range agriculture, intensive horticulture, of measures that include: recreation, rural living, tourism, • accelerating sewering of major towns environmental conservation and • fencing our rivers and streams urban environments. These multiple uses place pressure on the water •undertaking more comprehensive and resource and can impact on water targeted monitoring programmes quality. •providing resources for compliance management Large storage reservoirs have been constructed on some of the numerous •undertaking education and awareness rivers and streams of the Mount Lofty raising programmes on activities that Ranges to harvest its relatively high can impact on water quality. rainfall and supply Adelaide with The five-year programme is significant drinking water. This drinking water and targeted at improving water quality is supplemented with water from the and reducing the risks. Long term water River Murray. However, water collected quality improvements can only be within the catchments is a significant achieved if we all work together. component of the total supply needs of Adelaide. The issue of providing safe drinking water is a priority. The higher rainfall and richer soils have meant that the Mount Lofty Ranges are used quite extensively for agriculture. Many people now live and work in towns and villages nestled in once pristine river valleys to take John Olsen FNIA MP advantage of the climate and appeal Premier of South Australia of the ranges. Protecting and improving water quality in the Mount Lofty Ranges watershed is fundamental to the welfare of most South Australians. Foreword Major catchments Figure 1. in the Mount Lofty Major Mt Lofty Ranges Catchments Ranges Mt Lofty Ranges Watershed Wider Mt Lofty Ranges Catchments Area Rivers and Streams Light Kapunda Tanunda Gawler Gawler Marne Williamstown Gulf St Vincent Mt Pleasant Torrens Adelaide Stirling River Murray Mt Barker Onkaparinga Bremer-Barker Murray Bridge Angas Finniss Myponga Lake Alexandrina Hindmarsh Victor Harbor Currency Creek 1. Introduction Issues relating Some of the causes of Measures being taken to these issues are: tackle these issues to water include: •poorly maintained septic tank systems quality some of which discharge raw sewage • Domestic wastewater into the rivers and streams of the treatment systems are The Mount Lofty Ranges catchments catchment being audited and (Figure 1) are a significant source of drinking water for Adelaide and home •livestock access to watercourses required to comply with to a number of important aquatic which causes rapid erosion of health regulations. waterways and the movement of environments. Unlike the water • The programme to sewer sediment into weirs and reservoirs supply catchments of most other the major towns of Australian capital cities they are also •overgrazing, coupled with heavy Aldgate, Stirling and an important region for agriculture, rainfall, which erodes soils Bridgewater is being and urban and rural living. Over time, •cropping on steep valley slopes which accelerated. this has led to fundamental landuse contributes to extensive soil erosion • Additional funds will be conflicts that have resulted in a and delivers large amounts of number of water quality issues. provided to speed up sediment and nutrients into streams restoration of rivers The purpose of this document is to •past swamp drainage, to clear land for and streams. raise awareness of these issues, and agriculture, which can trigger stream to outline measures that are being bed deepening • Farm dam regulations undertaken to improve water quality. are being reviewed and •large numbers of farm dams which existing farm dams Water quality issues reduce the flow of many major watercourses assessed. include: •past planning practices which have • Planning strategies are •blooms of toxic algae in dams and allowed some inappropriate being reviewed with a reservoirs development in water supply stronger focus on water •major reservoirs closed because of catchments. quality. contamination of water by algae •Education programmes •stock deaths from animals drinking will be increased targeting water contaminated by toxic algae activities that impact on •pesticides causing contamination in water quality. some rivers and streams •water-borne parasites, Cryptosporidium and Giardia, detected in rivers and streams •sediment from erosion of degraded river banks, overgrazing and intensive horticultural practices deposited in reservoirs •animal and human faecal contamination of rivers and streams making them unsuitable for drinking without disinfection • localised heavy metal contamination. 3. The Gorge Why are the Weir (EPA). Mount Lofty Ranges important? The catchments of the Mount Lofty Ranges cover an area of more than 4000 square kilometres and contain many significant natural and economic resources. Early settlers determined the landuse character of the ranges within the first 50 years of settlement in South Australia. The main activities Land uses within our During the 1970s this changed with the were market gardening, fruit growing, Mount Lofty Ranges implementation of measures to control cropping, grazing and mining. These township development and intensive landuses continue today. •Local runoff from the catchments animal keeping activities in watersheds. contributes up to 60% of Adelaide’s Since settlement, the Mount Lofty water supply. Ranges catchments have also been Today, the issue of maintaining •The area is a major source of dairy, a major source of Adelaide’s water market garden and horticultural good water quality for the supply. Extraction for the city of products. Adelaide metropolitan area has Adelaide began in 1860 with the assumed great importance. construction of the Gorge Weir. •Different activities, such as forestry, Other reservoirs, Barossa (1902), viticulture, quarrying, intensive The five-year, $40 million Warren (1916), Millbrook (1918), horticulture, grazing and many programme to improve the Mount Bold (1938), South Para others, compete for resources. Mount Lofty Ranges catchments (1958), Myponga (1962) and •There are 160 townships and over clearly indicates that the issue of Kangaroo Creek (1969) were built 88 000 people living in the Mount maintaining good water quality to meet Adelaide’s growing demand Lofty Ranges. is a key Government priority. for water. As supplies of water are The significant demands on land in the This programme will include: variable from year to year, water is Mount Lofty Ranges can impact on • accelerating sewering of major piped from the River Murray and water resources. stored in Mount Bold, Millbrook and towns Although water quality issues arose as Kangaroo Creek reservoirs. Pumping • fencing rivers and streams to the River Torrens began in 1953 early as the 1880s, in the early years • undertaking more and to the Onkaparinga River in there was little attempt to control 1957. A second pipeline to the activities along major waterways. comprehensive and targeted Onkaparinga was completed in 1974. Rather, settlement and agricultural monitoring programmes development were given priority over • providing resources for the need to maintain catchments for compliance management water supplies. • undertaking education and awareness raising programmes on activities that can impact on water quality. 4. An aerial view of Mount Bold reservoir, surrounded by a patch­ work of different landuses (EPA). How have our • Only 1% of the stream network Improvements already of the Adelaide Hills has riparian implemented include: vegetation that is described as being Mount Lofty in a healthy condition. •No broadacre clearance is permitted. Ranges The Mount Lofty Ranges are unique changed? in Australia. Nowhere else does a • Over 60 km of streams metropolitan area depend for water have been revegetated. The rate of change throughout the supplies on catchments that are • Woody weeds have been ranges since settlement has been intensively used for living, industry removed from over 90 km significant. In recent years improved and agriculture. of streams. roads and quicker access have Nor does any other capital city resulted in significant population • More than 48 km of depend so greatly on the River Murray,